The present invention relates to the conversion of hydrocarbon containing oils into lighter fractions by cracking in the presence of a zeolite-containing cracking catalyst.
Most commercial cracking operations today employ a zeolite-containing cracking catalyst. Generally the cracking process involves contacting the cracking catalyst with steam during certain portions of the process. Examples include the use of steam to remove absorbed or entrained hydrocarbons from catalyst removed from the cracking zone and the use of steam to transfer new catalyst and regenerated used catalyst back to the cracking zone.
It has been noted by many that the steam has an adverse effect upon the surface area of the zeolite which in turn has an adverse effect on the activity of the cracking catalyst.
An object of the present invention is to provide a means for counteracting at least some of the adverse effects that steam has on zeolite-containing cracking catalysts.